Suwansonthichai Sasithorn, Rengpipat Sirirat
Department of Medical Sciences, Ministry of Public Health, Nonthaburi 11000, Thailand.
Int J Food Microbiol. 2003 Mar 15;81(2):113-21. doi: 10.1016/s0168-1605(02)00190-3.
Conventional (most probable number, MPN) and rapid methods-including Chromocult coliform agar (CCA), Fluorocult(R) LMX broth (LMX), and Petrifilm Escherichia coli count plates (PEC) for enumeration of coliforms and E. coli in frozen black tiger shrimp from Thailand were compared in order to assess the possibility of using one of the rapid methods for routine analysis. Enumeration of coliforms and E. coli from 18 samples of regular frozen black tiger shrimp and 156 samples of frozen black tiger shrimp experimentally contaminated with coliforms or E. coli at concentrations of approximately 10, approximately 10(2), and approximately 10(3) CFU g(-1) revealed that at the level of approximately 10 CFU g(-1), coliform numbers ranked as LMX>CCA>MPN=PEC and E. coli as MPN=LMX=PEC=CCA. At the level of approximately 10(2) CFU g(-1), coliform numbers ranked as LMX>MPN=PEC=CCA and E. coli as MPN=LMX>PEC=CCA. At the level of 10(3) CFU g(-1), coliforms ranked as LMX>MPN=CCA>PEC and E. coli as MPN>LMX>CCA>PEC. Agreements with the conventional MPN method for coliforms were LMX 108%, PEC 87.2%, and CCA 91.2% and agreements for E. coli were LMX 101%, PEC 95.7%, and CCA 96.3%. Sensitivities (%) ranked LMX>MPN>CCA=PEC for coliforms and E. coli, whereas equal specificities (100%) of all methods for coliforms and E. coli were demonstrated. Rankings for the other parameters compared were: convenience, PEC>CCA=LMX>MPN; time to detection, MPN>LMX=PEC=CCA; expense, MPN=PEC>CCA>LMX; labor, MPN>LMX=CCA>PEC; accuracy for coliforms, PEC>CCA>MPN>LMX; and accuracy for E. coli, PEC=CCA>LMX>MPN.
对常规（最大可能数法，MPN）和快速方法——包括用于计数泰国冷冻黑虎虾中大肠菌群和大肠杆菌的Chromocult大肠菌群琼脂（CCA）、Fluorocult（R）LMX肉汤（LMX）和Petrifilm大肠杆菌计数平板（PEC）进行了比较，以评估使用其中一种快速方法进行常规分析的可能性。对18份常规冷冻黑虎虾样品以及156份经实验分别污染了浓度约为10、约10²和约10³CFU g⁻¹大肠菌群或大肠杆菌的冷冻黑虎虾样品中的大肠菌群和大肠杆菌进行计数，结果显示，在约10 CFU g⁻¹水平时，大肠菌群数量排序为LMX>CCA>MPN = PEC，大肠杆菌数量排序为MPN = LMX = PEC = CCA。在约10²CFU g⁻¹水平时，大肠菌群数量排序为LMX>MPN = PEC = CCA，大肠杆菌数量排序为MPN = LMX>PEC = CCA。在10³CFU g⁻¹水平时，大肠菌群排序为LMX>MPN = CCA>PEC，大肠杆菌排序为MPN>LMX>CCA>PEC。与常规MPN方法相比，大肠菌群的一致性方面，LMX为108%，PEC为87.2%，CCA为91.2%；大肠杆菌的一致性方面，LMX为101%，PEC为95.7%，CCA为96.3%。大肠菌群和大肠杆菌的灵敏度（%）排序为LMX>MPN>CCA = PEC，而所有方法对大肠菌群和大肠杆菌的特异性均为100%。所比较的其他参数排序如下：便利性，PEC>CCA = LMX>MPN；检测时间，MPN>LMX = PEC = CCA；成本，MPN = PEC>CCA>LMX；工作量，MPN>LMX = CCA>PEC；大肠菌群准确性，PEC>CCA>MPN>LMX；大肠杆菌准确性，PEC = CCA>LMX>MPN。
